Wildlife & Habitat

After World War II, the brown tree snake was accidentally introduced into Guam. With no natural predators and abundant prey, the snake population steadily grew and spread throughout the island. As the snakes dispersed, forest bird and fruit bat populations plummeted. By the late 1980s, 12 species of birds and the little Mariana fruit bat had disappeared from Guam. The Refuge provides habitat for the last remaining populations of the endangered Mariana fruit bat, Mariana crow, and the Serianthes nelsonii tree. The brown tree snake is considered the primary cause for the decline of native Guam bird species.

Birds

Mariana crow - The "aga" is a small black crow with a slight greenish-black gloss on its head, back, underparts, and wings. Its tail has a bluish-black gloss. Females are smaller than the males.

Mammals

The "fanihi" is a medium-sized bat measuring 195 to 250 mm from head to rump, with a wingspan of 860 to 1065 mm. The males are slightly larger than the females. The abdomen and wings are dark brown to black with individual gray hairs intermixed throughout the fur. The mantle and sides of the neck are bright gold on most animals but in some individuals, this region may be pale gold or pale brown. The color of the head varies from brown to dark brown.

Reptiles

Haggan (green turtles) are characterized by a smooth carapace with four pairs of lateral scutes and a coarsely serrated lower jaw-edge. The hawksbill named for its narrow head and sharp, bird-like beak, hawksbills can reach into cracks and crevices of coral reefs looking for food.

Habitat

Serianthes nelsonii - One of the largest native trees in the Mariana Islands that is found no where else in the world occurs on limestone-derived soils on Rota and Guam. Most of the trees on Rota grow on or near steep hillsides and cliffs at elevations of 490-1,380 feet (150-420 meters) on the western side of the island. Trees in Guam were known to grow at elevations of 400-575 feet (120-175 meters).

What We Do

Guam Rail or Ko'ko

A flightless bird, the Ko’ko is omnivorous and prefers mixed forest. It is easy prey for monitor lizards, cats, rats, and the brown tree snake. Breeding programs have been set up to eventually reintroduce this treasured bird to Guam.